Paenibacillus suaedae sp. nov. and Paenibacillus violae sp. nov., isolated from the roots of Suaeda japonica Makino and Viola mandshurica W. Becker with plant growth-promoting potential

Two novel Gram-positive strains, chi10^T and PFR10^T, were isolated from the roots of <i>Suaeda japonica</i> Makino and <i>Viola mandshurica</i> W. Becker, respectively. The strains are facultatively aerobic, rod-shaped, motile via peritrichous flagella and endospore-forming. Strains chi10^T and PFR10^T showed the highest 16S rRNA gene sequence similarity to <i>Paenibacillus alvei</i> DSM 29^T (99.0%) and <i>Paenibacillus planticolens</i> LMG 31457^T (99.3%). Furthermore, the phylogenetic and phylogenomic analyses demonstrated that strains chi10^T and PFR10^T were closely related to the genus <i>Paenibacillus</i>. The digital DNA-DNA hybridization (dDDH) values for strains used in the phylogenetic analysis and strain chi10^T ranged from 19.6 to 28.4%, while for strain PFR10^T, the values ranged from 19.8 to 53.5%, according to the Genome-to-Genome Distance Calculator 3.0, which were all less than 70%. Additionally, the dDDH value between strains chi10^T and PFR10^T was 22.0%, confirming that they are different species of the genus <i>Paenibacillus</i>. The average nucleotide identity between chi10^T and PFR10^T and other species of the genus <i>Paenibacillus</i> were 68.4-84.7% and 67.8-93.6%, respectively. In addition, the major polar lipids of chi10^T and PFR10^T consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acid profile of strain chi10^T was iso-C_{15 : 0} and anteiso-C_{15 : 0}, whereas the major fatty acid profile of strain PFR10^T was iso-C_{15 : 0}, anteiso-C_{15 : 0} and iso-C_{16 : 0}. The sole respiratory quinone in strains chi10^T and PFR10^T was menaquinone-7. Phylogenomic, phenotypic and genome analyses strongly indicated that chi10^T and PFR10^T could be two novel <i>Paenibacillus</i> species for which the names <i>Paenibacillus suaedae</i> sp. nov. (type strain chi10^T = KACC 23258^T = TBRC 17803^T) and <i>Paenibacillus violae</i> sp. nov. (type strain PFR10^T = KACC 23263^T = TBRC 17804^T) are proposed, respectively.